Processors, like most integrated circuits, require a direct current to operate. A direct current (DC) may be produced by a power supply associated with a system in which the processor resides. While the power supply may produce a first direct current with a first voltage (e.g., 12V), a processor may require a different direct current with a second voltage (e.g., 5V, 2.5V, 1.25V). Thus, many computing systems may include a DC-DC converter that is configured to produce a second direct current from a first direct current.
While a processor may require a direct current with certain properties (e.g., 1.5V), it is to be appreciated that a “perfect” voltage may not be achievable and/or constantly maintainable. Thus, various properties may be acceptable in a direct current provided to a processor so long as they fall within a range that the processor can tolerate. For example, a direct current with a voltage of 1.5V+/−2% may be acceptable. However, if the direct current voltage falls outside the acceptable range, a processor may not be able to continue to operate properly. This may lead to a processor simply halting, which in turn may lead to the loss of data, state, and so on. The direct current voltage may fall out of a specified range due to reasons like, a component wearing out, a power supply becoming defective, and so on.
Certain types of processors may be referred to as charge-rationed processors. A charge-rationed processor may be, for example, a frequency scalable processor. These types of processors may require a direct current with properties that vary based on desired operating characteristics for the processor. For example, to operate at a first frequency, a charge-rationed processor may require a direct current with a first voltage. To operate at a second frequency, the charge-rationed processor may require a direct current with a second voltage. In general, higher operating frequencies require higher voltages and lower operating frequencies may be supported with lower voltages. There are definable relationships between the voltages, currents, frequencies, and so on, associated with charge-rationed processors. For example the equations:V=IR, (where V=voltage, I=current, R=resistance)P=VI, (where P=power), andP≈C f V2, (where f=frequency)
are useful for describing example relationships between various properties.